CN104641414A

CN104641414A - Stereo audio signal encoder

Info

Publication number: CN104641414A
Application number: CN201280075873.8A
Authority: CN
Inventors: A·瓦西拉凯; L·J·拉克索宁; A·S·拉莫
Original assignee: Nokia Oyj
Current assignee: Nokia Technologies Oy
Priority date: 2012-07-19
Filing date: 2012-07-19
Publication date: 2015-05-20
Also published as: US9865269B2; EP2875510A4; US20150310871A1; WO2014013294A1; EP2875510A1

Abstract

An apparatus comprising: a channel analyser configured to determine at least one set of parameters defining a difference between at least two audio signal channels; a value analyser configured to analyse the at least one set of parameters to determine an initial trend; a mapper configured to map instances of the at least one set of parameters according to a first mapping to generate mapped instances with associated order position instances based on the initial trend; and an encoder configured to encode the mapped instances based on the order position of the mapped instances.

Description

Stereo audio signal scrambler

Technical field

The present invention relates to stereo audio signal scrambler, and especially but not exclusively relate to the stereo audio signal scrambler used in portable set.

Background technology

Sound signal, as voice or music, such as, is encoded to make it possible to effectively transmission or stored audio signal.

Audio coder and demoder (being also referred to as codec) are used to represent the signal based on audio frequency, as music and ambient sound (it can be called as background noise in voice coding).The scrambler of these types does not use speech model usually for coded treatment, and they use for representing the process comprising all types of sound signal of voice.Speech coder and demoder (codec) can be considered to the audio codec optimized for voice signal, and can at fixing or variable bit rate operation.

Audio codec also can be configured to operate with different bit rates.At comparatively low bit rate place, such audio codec can be optimized to the code rate equal with pure audio coder & decoder (codec) to voice signal work.At higher bit rate place, audio codec can comprise any signal of music, ground unrest and voice with higher quality and performance coding.Variable bit rate audio coder-decoder can also realize embedded ges forschung structure and bit stream, wherein, additional bit (bit of specified quantitative is commonly called layer) improves the coding at low rate place, and wherein the bit stream of higher rate can be truncated to obtain the bit stream compared with low rate coding.Such audio coder-decoder can utilize encodes as core layer or lowest bit rate for the codec of voice signal design purely.

Audio codec is designed to keep high (perception) quality, improves ratio of compression simultaneously.Thus replace Waveform Matching coding, usually use various parametric scheme to reduce bit rate.For multichannel audio, such as stereophonic signal, usually uses relatively large Available Bit Rate and utilizes parametric method to come encoded stereo or multi-channel information on monophony represents, the method uses relatively less bit.

Summary of the invention

According to first aspect, a kind of method is provided, comprises: at least one parameter sets determining to define the difference between at least two audio signal channels; Analyze at least one parameter sets described to determine initial trend; Based on described initial trend, map according to first and map the example of at least one parameter sets, with generate have shut sequence examples of locations through map example; And based on the described ordinal position through map example, encode described through map example.

The method may further include: determine at least one subsequent parameter; Depend on through map example frequency distribution and first map, map described subsequent instance with generate have shut sequence position through the example that remaps; And based on the described ordinal position through the example that remaps, encode described through the example that remaps.

Parameter can comprise following at least one: the mistiming between ears; And the level difference between ears.

The method may further include the example of parameter described in scalar quantization.

Analyze at least one parameter sets described with determine initial trend can comprise determine following at least one: the entirety of at least one parameter sets described all have on the occasion of; The entirety of at least one parameter sets described has negative value; The great majority of at least one parameter sets described have on the occasion of; The great majority of at least one parameter sets described have negative value; The entirety of at least one parameter sets described has lower-magnitude value; The entirety of at least one parameter sets described has higher range value; With the entirety of at least one parameter sets described, there is the range value of scope restriction.

Based on described initial trend, map and map the example of at least one parameter sets, have can comprising through map example of shut sequence examples of locations: generate initial mapping to generate according to first, wherein said initial Trend value is assigned lower or comparatively early order.

The method may further include: determine that first through the frequency distribution of map example group.

Determine that first can comprise through the frequency distribution of map example group: for the described first each in map example group, receive described first through map example value; Increase progressively and the described first count value be associated through map example value; To successively decrease the count value be associated with except the described first example value except map example value.

Depend on the described ordinal position through map example, encoding describedly can comprise through map example: depend on the described ordinal position through map example, is applied to described through map example by Golomb-Rice coding.

The method may further include: generate and represent the described first designator mapped; With encoded monophony is represented, encoded map example and represent first map designator carry out multiplexing, to generate encoded multi-channel audio signal; With the encoded multi-channel audio signal of output.

According to second aspect, a kind of method is provided, comprises: from the Part I decoding parametric example of signal and from Part II decoding parametric trend designator; With depend on parameter trend designator, map described examples of parameters with generating solution mapping parameters example, parameter trend designator is depended in wherein said mapping.

The method may further include: to decode another instance parameter from the Part I of signal; With the frequency distribution depending on demapping examples of parameters, map another examples of parameters described.

Can comprise from the Part I decoding parametric example of signal: use Golomb-Rice decoding to decode to the Part I of signal.

The method may further include: the frequency distribution determining described examples of parameters.

Determine that the frequency distribution of described examples of parameters can comprise: for the examples of parameters group of described demapping, keep the counting of described demapping examples of parameters.

Map described examples of parameters can comprise: depend on that the order of occurrence that successively decreases for the frequency distribution through the examples of parameters that remaps maps, determine inverse mapping; With application inverse mapping.

According to the third aspect, a kind of equipment comprising at least one processor and at least one storer is provided, described storer comprises the computer code for one or more program, and at least one storer described and described computer code are configured to together with at least one processor described, described equipment at least be performed: at least one parameter sets determining to define the difference between at least two audio signal channels; Analyze at least one parameter sets described to determine initial trend; Based on described initial trend, map according to first and map the example of at least one parameter sets, with generate have shut sequence examples of locations through map example; And based on the described ordinal position through map example, encode described through map example.

Described equipment can be made to perform further: determine at least one subsequent parameter; Depend on through map example frequency distribution and first map, map described subsequent instance with generate have the ordinal position that is associated through the example that remaps; And based on the described ordinal position through the example that remaps, encode described through the example that remaps.

Described equipment can be made to perform further: the example of parameter described in scalar quantization.

Analyze at least one parameter sets described to determine that initial trend can make this equipment perform: determine following at least one: the entirety of at least one parameter sets described all have on the occasion of; The entirety of at least one parameter sets described has negative value; The great majority of at least one parameter sets described have on the occasion of; The great majority of at least one parameter sets described have negative value; The entirety of at least one parameter sets described has lower-magnitude value; The entirety of at least one parameter sets described has higher range value; With the entirety of at least one parameter sets described, there is the range value of scope restriction.

Based on described initial trend, the example mapping at least one parameter sets is mapped according to first, with generate there is the ordinal position example that is associated this equipment can be made to perform through map example: generate initial mapping, wherein said initial Trend value is assigned lower or comparatively early sequentially.

Described equipment can be made to perform further: determine that first through the frequency distribution of map example group.

Determine that first can make this equipment perform through the frequency distribution of map example group: for the described first each in map example group, receive described first through map example value; Increase progressively and the described first count value be associated through map example value; To successively decrease the count value be associated with except the described first example value except map example value.

Depend on the described ordinal position through map example, encoding describedly can make this equipment perform through map example: depend on the described ordinal position through map example, is applied to described through map example by Golomb-Rice coding.

Described equipment can be made to perform further: generate and represent the described first designator mapped; With encoded monophony is represented, encoded map example and represent first map designator carry out multiplexing, to generate encoded multi-channel audio signal; With the encoded multi-channel audio signal of output.

According to fourth aspect, a kind of equipment comprising at least one processor and at least one storer is provided, described storer comprises the computer code for one or more program, and at least one storer described and described computer code are configured to together with at least one processor described, described equipment at least be performed: from the Part I decoding parametric example of signal and from Part II decoding parametric trend designator; With depend on parameter trend designator, map described examples of parameters with generating solution mapping parameters example, parameter trend designator is depended in wherein said mapping.

Described equipment can be made to perform further: to decode another instance parameter from the Part I of signal; With the frequency distribution depending on demapping examples of parameters, map another examples of parameters described.

This equipment can be made to perform from the Part I decoding parametric example of signal: to use Golomb-Rice decoding to decode to the Part I of signal.

Described equipment can be made to perform further: the frequency distribution determining described examples of parameters.

Determine that the frequency distribution of described examples of parameters can make this equipment perform: for the examples of parameters group of described demapping, keep the counting of described demapping examples of parameters.

Mapping described examples of parameters can make this equipment perform: depend on that the order of occurrence that successively decreases for the frequency distribution through the examples of parameters that remaps maps, determine inverse mapping; With application inverse mapping.

According to the 5th aspect, a kind of equipment is provided, comprises: for determining the device of at least one parameter sets of the difference defined between at least two audio signal channels; For analyzing at least one parameter sets described to determine the device of initial trend; For based on described initial trend, map the example mapping at least one parameter sets, to generate the device through map example with shut sequence examples of locations according to first; And for based on the described ordinal position through map example, the described device through map example of encoding.

Described equipment may further include: for determining the device of at least one subsequent parameter; For depending on that the frequency distribution and first through map example maps, map described subsequent instance to generate the device through the example that remaps with shut sequence position; And for based on the described ordinal position through the example that remaps, the described device through the example that remaps of encoding.

Described equipment may further include: for the device of the example of parameter described in scalar quantization.

For analyzing at least one parameter sets described to determine that the device of initial trend can comprise: for determine following in the device of at least one: the entirety of at least one parameter sets described all have on the occasion of; The entirety of at least one parameter sets described has negative value; The great majority of at least one parameter sets described have on the occasion of; The great majority of at least one parameter sets described have negative value; The entirety of at least one parameter sets described has lower-magnitude value; The entirety of at least one parameter sets described has higher range value; With the entirety of at least one parameter sets described, there is the range value of scope restriction.

For based on described initial trend, the example mapping at least one parameter sets is mapped according to first, can comprise to generate the device through map example with the ordinal position example that is associated: for generating the device of initial mapping, wherein said initial Trend value is assigned lower or comparatively early order.

Described equipment may further include: for determining that first through the device of the frequency distribution of map example group.

For determining that first can comprise through the device of the frequency distribution of map example group: for for the described first each in map example group, receive described first through the device of map example value; For increasing progressively the device with the described first count value be associated through map example value; For the device of the count value be associated with except the described first example value except map example value of successively decreasing.

For depending on the described ordinal position through map example, the described device through map example of encoding can comprise: for depending on the described ordinal position through map example, and Golomb-Rice coding is applied to the described device through map example.

Described equipment may further include: for generating the device representing the described first designator mapped; With for representing encoded monophony, encoded map example and represent first map designator carry out multiplexing, to generate the device of encoded multi-channel audio signal; With the device for exporting encoded multi-channel audio signal.

According to the 6th aspect, a kind of equipment is provided, comprises: for from the Part I decoding parametric example of signal and from the device of Part II decoding parametric trend designator; With for depending on parameter trend designator, map described examples of parameters with the device of generating solution mapping parameters example, parameter trend designator is depended in wherein said mapping.

Described equipment may further include: for the device of another instance parameter of decoding from the Part I of signal; With the frequency distribution for depending on demapping examples of parameters, map the device of another examples of parameters described.

Device for the Part I decoding parametric example from signal can comprise: to decode the device of decoding to the Part I of signal for using Golomb-Rice.

Described equipment may further include: for determining the device of the frequency distribution of described examples of parameters.

For determining that the device of the frequency distribution of described examples of parameters can comprise: for the examples of parameters group for described demapping, keep the device of the counting of described demapping examples of parameters.

Device for mapping described examples of parameters can comprise: for depending on that the order of occurrence that successively decreases for the frequency distribution through the examples of parameters that remaps maps, determine the device of inverse mapping; With the device for applying inverse mapping.

According to the 7th aspect, a kind of equipment is provided, comprises: sound channel analyzer, be configured at least one parameter sets determining to define the difference between at least two audio signal channels; Digital analyzer, is configured to analyze at least one parameter sets described to determine initial trend; Mapper, is configured to based on described initial trend, maps map the example of at least one parameter sets according to first, with generate have shut sequence examples of locations through map example; And scrambler, be configured to, based on the described ordinal position through map example, encode described through map example.

Described sound channel analyzer can be configured to determine at least one subsequent parameter further; Described mapper can be configured to depend on that the frequency distribution and first through map example maps further, map described subsequent instance with generate have shut sequence position through the example that remaps; And described scrambler can be configured to, based on the described ordinal position through the example that remaps, encode described through the example that remaps further.

Described equipment can comprise scalar quantizer, is configured to the example of parameter described in scalar quantization.

Described analyzer can be configured to determine following at least one: the entirety of at least one parameter sets described all have on the occasion of; The entirety of at least one parameter sets described has negative value; The great majority of at least one parameter sets described have on the occasion of; The great majority of at least one parameter sets described have negative value; The entirety of at least one parameter sets described has lower-magnitude value; The entirety of at least one parameter sets described has higher range value; With the entirety of at least one parameter sets described, there is the range value of scope restriction.

Mapper can comprise initial mapping device, is configured to generate initial mapping, and wherein said initial Trend value is assigned lower or comparatively early order.

Described equipment can comprise counter, is configured to determine that first through the frequency distribution of map example group.

Described counter can comprise: input, to be configured to for described first, through each of map example group, receive described first through map example value; Incrementor, is configured to increase progressively and the described first count value be associated through map example value; And demultiplier, be configured to successively decrease the count value be associated with except the described first example value except map example value.

Scrambler can comprise: Golomb-Rice scrambler, is configured to depend on the described ordinal position through map example, is applied to described through map example by Golomb-Rice coding.

Described equipment may further include: initial mapping indicator, is configured to generate represent the described first designator mapped; And multiplexer, be configured to represent encoded monophony, encoded map example and represent that the first designator mapped carries out multiplexing, to generate encoded multi-channel audio signal; And output, be configured to export encoded multi-channel audio signal.

According to eighth aspect, a kind of equipment is provided, comprises: demoder, be configured to Part I decoding parametric example from signal and from Part II decoding parametric trend designator; And mapper, be configured to depend on parameter trend designator, map described examples of parameters with generating solution mapping parameters example, parameter trend designator is depended in wherein said mapping.

Described demoder can be configured to decode another instance parameter from the Part I of signal further; Can be configured to described mapper the frequency distribution depending on demapping examples of parameters further, map another examples of parameters described.

Described demoder can comprise Golomb-Rice demoder.

Described equipment can comprise symbol count renovator, is configured to the frequency distribution determining described examples of parameters.

Described symbol count renovator can be configured to the examples of parameters group for described demapping, keeps the counting of described demapping examples of parameters.

Described mapper can comprise: inverse mapper, is configured to depend on that the order of occurrence that successively decreases for the frequency distribution through the examples of parameters that remaps maps, and determines inverse mapping; With inverse mapping processor, be configured to apply inverse mapping.

Described parameter can comprise following at least one: the mistiming between ears; And the level difference between ears.

A kind of computer program can make equipment perform method as herein described.

A kind of electronic installation can comprise equipment as herein described.

A kind of chipset can comprise equipment as herein described.

Accompanying drawing explanation

In order to understand the present invention better, now carry out reference, in accompanying drawing by the example of accompanying drawing:

Fig. 1 schematically shows the electronic equipment using some embodiments;

Fig. 2 schematically shows the audio codec system according to some embodiments;

Fig. 3 schematically shows according to some embodiments scrambler as shown in Figure 2;

Fig. 4 schematically illustrates in greater detail according to some embodiments sound channel analyzer as shown in Figure 3;

Fig. 5 schematically illustrates in greater detail according to some embodiments stereo channels scrambler as shown in Figure 3;

Fig. 6 shows process flow diagram, and the operation according to some embodiments scrambler is as shown in Figure 2 described;

Fig. 7 shows process flow diagram, and the operation according to some embodiments sound channel analyzer is as shown in Figure 4 described;

Fig. 8 shows process flow diagram, and the operation according to some embodiments channel encoder is as shown in Figure 5 described;

Fig. 9 schematically shows according to some embodiments demoder as shown in Figure 2;

Figure 10 shows process flow diagram, and the operation according to some embodiments demoder is as shown in Figure 9 described; And

Figure 11 to Figure 13 shows the example sound channel signal, coding channels and the coding channels sound signal that use embodiment.

Specific implementation

Below describe in further detail possible stereo and multichannel voice and audio codec, comprise layering or scalable variable rate voice and audio codec.With regard to this respect, first carry out reference to Fig. 1, Fig. 1 shows the schematic block diagram of exemplary electronic device or equipment 10, and it can be incorporated to the codec according to the embodiment of the present application.

Equipment 10 can be such as mobile terminal or the subscriber equipment of wireless communication system.In other embodiments, equipment 10 can be voice-frequency sender or audio player, the medium recorder (also referred to as MP4 recorder/player) of audio-visual devices, such as MP3 recorder/player and so on of such as video camera, TV (TV) receiver and so on, or is suitable for any computing machine of Audio Signal Processing.

In certain embodiments, electronic installation or equipment 10 comprise microphone 11, and it is linked to processor 21 via AD converter (ADC) 14.Processor 21 is linked to loudspeaker 33 further by digital to analogy (DAC) converter 32.Processor 21 is also linked to transceiver (RX/TX) 13, is linked to user interface (UI) 15 and is linked to storer 22.

Processor 21 can be configured to perform various program code in certain embodiments.The program code realized in certain embodiments comprises multichannel as described herein or stereo coding or decoding code.The program code 23 realized such as can be stored in storer 22 in certain embodiments for often being fetched by processor 21 when needed.Storer 22 can be provided for the part 24 storing data (such as according to the coded data of the application) further.

Code And Decode code in an embodiment can realize in hardware and/or firmware.

User interface 15 enables user such as input instruction to electronic installation 10 by keypad, and/or such as obtains the information from electronic installation 10 via display.In certain embodiments, touch-screen can be provided for the input and output function of user interface.In certain embodiments, equipment 10 comprise be suitable for such as via cordless communication network can with the transceiver 13 of the communication of miscellaneous equipment.

But should again understand, the structure of equipment 10 can be added or change in many ways.

The user of equipment 10 such as can use microphone 11 will be sent to some miscellaneous equipments maybe will be stored in voice in the data division 24 of storer 22 or other sound signal for inputting.In certain embodiments, corresponding application can be activated by a user via user interface 15 for this reason.In these embodiments, this application can be performed by processor 21, makes processor 21 perform the code be stored in storer 22.

In certain embodiments, AD converter (ADC) 14 converts the simulated audio signal of input to digital audio and video signals, and provides this digital audio and video signals to processor 21.In certain embodiments, microphone 11 can comprise integrated microphone and ADC function, and provides digital audio and video signals for process directly to processor.

In this type of embodiment, processor 21 is then with the identical mode process digital audio and video signals described by system, the scrambler as shown in Fig. 2 to Fig. 8 and the demoder as shown in figs. 9 and 10 as shown in reference to figure 2.

In certain embodiments, the bit stream obtained can be provided to transceiver 13 for another device transmission.Alternatively, in certain embodiments, encoded voice data can be stored in the data division 24 of storer 22, such as with by identical equipment 10 for transmission after a while or for presenting after a while.

In certain embodiments, equipment 10 can also receive the bit stream with corresponding coded data via transceiver 13 from another equipment.In this illustration, processor 21 can perform the decoding process code be stored in storer 22.In such embodiments, processor 21 is decoded the data received, and provides decoded data to digital-to-analog converter 32.Digital decoded data is converted to analog audio data by digital-to-analog converter 32, and can export analogue audio frequency via loudspeaker 33 in certain embodiments.The execution of decoding process code in certain embodiments can be triggered by the application of being called by user via user interface 15.

In certain embodiments, replace presenting immediately via loudspeaker 33, the coded data received also can be stored in the data division 24 of storer 22, such as, for decoding after a while and presenting or decode and be forwarded to another equipment.

Should be appreciated that, schematic structure described in Fig. 3 to Fig. 5 and Fig. 9, and the method step shown in Fig. 6 to Fig. 8 and Figure 10 only represents stereophonic encoder/decoder apparatus in equipment shown in Fig. 1 of realization as schematically shown or the specific part of method and the part operation of audio codec.

The general operation of the audio codec that embodiment uses is shown in Figure 2.As in Figure 2 schematically illustrated, general audio coding/decoding system comprises both encoder.But should be appreciated that, some embodiments can realize one of scrambler or demoder, or both encoder.Shown in Fig. 2 is system 102, has scrambler 104 and especially has stereophonic encoder 151, storage or media sound channel 106 and demoder 108.Should be appreciated that, more above-mentioned embodiments can comprise or realize both one of scrambler 104 or demoder 108 or scrambler 104 and demoder 108.

Scrambler 104 compresses the sound signal 110 of input, and produce bit stream 112, it can be stored in certain embodiments or be launched by media sound channel 106.Scrambler 104 can also comprise the stereophonic encoder 151 as a whole encoding operation part.Should be appreciated that, stereophonic encoder can be a part or the independently coding module of whole scrambler 104.Scrambler 104 can also comprise multi-channel encoder, its coding two or more sound signal.

Bit stream 112 can be received in demoder 108.Demoder 108 pairs of bit streams 112 decompress, and produce output audio signal 114.Demoder 108 can comprise the stereodecoder as a whole decode operation part.Should be appreciated that, stereodecoder can be a part for whole demoder 108 or independent decoder module.Demoder 108 can also comprise multi-channel decoder, its decoding two or more sound signal.About the principal character that the quality of the output audio signal 114 of input signal 110 and the bit rate of bit stream 112 are the performances defining coded system 102.

Fig. 3 schematically shows the scrambler 104 according to some embodiments.

Fig. 6 schematically shows the operation of the scrambler 104 according to some embodiments in flow charts.

Concept for embodiment as described herein attempts forming stereo or multi-channel encoder to produce high efficiency high-quality and low bitrate stereo or multi-channel signal coding.In integer coding device, the use of Golomb-Rice coding can produce the scrambler of the very low complex degree being suitable for providing good compression efficiency, and wherein data are exponential distribution.Wherein the unknown or loose situation of the quantity of coded identification such as can use Golomb-Rice code or entropy code.In addition, the Golomb-Rice of integer or entropy code can be performed, to reduce bit rate in quantization code vector index.

Should be appreciated that, the index of the subband level difference of the quantification in representing the ears of stereo audio signal is encoded and is created such numerical value, and wherein probability distribution changes significantly frame by frame.Therefore the entropy coder be configured to the mean value of data is encoded will produce suboptimum result.Although self-adaptation Golomb-Rice coding can produce larger benefit, they can have the response time slowly, and the adaptive characteristic of wherein encoding follows the tracks of the output quantized.

Therefore, in an embodiment, the adaptive entropy coding of low complex degree uses Golomb-Rice encoding scheme to describe to produce low bit rate and low encoding complexity device at this, but by the initial analysis of use information or by using the knowledge of the expection distribution of difference and the length of delay quantized, can define initial code to map, its tracking that can be reduced between coding that the initialization of coding and near optimal map postpones.Such as know a subset of only meeting assemble of symbol from the beginning, then can improve self-adaptation efficiency or optimize and follow the tracks of, wherein, employ the information that this is extra.Therefore, which symbol is concept described herein will to detect when using character subset (less different symbol is used) for present frame and signal by situation about using.In addition, this type of situation of this conceptual description wherein smallest number is considered, otherwise which symbol will be full of Available Bit Rate very soon by the information used about.In addition concept described herein is proposed definition further and is detected these situations, and the cataloged procedure of their correspondences.

Stereo coding pattern will be determined and apply to concept for embodiment described herein to produce high efficiency high-quality and the real-life coding of stereo signals of low bit rate.With regard in this respect, relative to Fig. 3, show the example encoder 104 according to some embodiments.In addition, relative to Fig. 6, the operation of scrambler 104 is illustrated in greater detail.

In certain embodiments, scrambler 104 comprises frame sectionaliser/transducer 201.Frame sectionaliser/transducer 201 is configured to receive left and right (or more generally, any multi-channel audio representation) input audio signal, and generates the frequency domain representation of these sound signals so that analyzed and coding.These frequency domain representations can be passed to channel parameters determiner 203.

In certain embodiments, frame sectionaliser/transducer can be configured to audio signal data segmentation or be divided into the segmentation or frame that are suitable for frequency domain conversion.In certain embodiments, frame sectionaliser/transducer 201 can be configured to carry out window operation according to any suitable window function to these frames of audio signal data or segmentation further.Such as, this frame sectionaliser/transducer 201 can be configured to generate the frame of 20ms, and it is for front and at each overlapping 10ms of rear frame.

In certain embodiments, frame sectionaliser/transducer can be configured to convert to frequency domain any suitable time domain of audio signal data execution.Such as time domain can be discrete Fourier transform (DFT) (DFT) to frequency domain conversion, fast fourier transform (FFT), the discrete cosine transform (MDCT) of amendment.In the following example, fast fourier transform (FFT) is used.In addition, time domain can be processed further to the output of frequency domain converter and to represent (subband represents) with the band domain of separating generating each input sound channel audio signal data.These frequency bands can be arranged in any suitable manner.Such as, these frequency bands can by spaced apart linearly, or by perception or psychologic acoustics distribute.

In certain embodiments, depending on the bandwidth for encoding to data, different sets of subbands can be there is.Such as, in certain embodiments, can be broadband (WB), ultra broadband (SWB) and the realization of Whole frequency band (FB) bandwidth coding, wherein SWB realizes realizing using more bit than WB, and FB realizes the more bit of use than SWB.In certain embodiments, use for different sound channel difference (as described herein), different subbands can be had.Such as, as described below, each of bandwidth for three are considered: broadband (WB), ultra broadband (SWB), and Whole frequency band (FB), can have specific sub-band division, they are slightly different with level differences (level) for delay.

/ * for postpone sub-band division */

The short scale 1024_WB [] of constant=

{1，5，8，12，20，34，48，56，120，512}；

The short scale 1024_SWB [] of constant=

{1，2，4，6，10，14，17，24，28，60，256，512}；

The short scale 1024_FB [] of constant=

{1，2，3，4，7，11，16，19，40，171，341，448/*～21kHz*/}；

/ * for level differences sub-band division */

The short scf_band_WB [] of constant=

{1，8，20，32，44，60，90，110，170，216，290，394，512}；

The short scf_band_SWB [] of constant=

{1，4，10，16，22，30，45，65，85，108，145，197，256，322，412，512}；

The short scf_band_FB [] of constant=

{1，3，7，11，15，20，30，43，57，72，97，131，171，215，275，341，391，448/*～21kHz*/}；

The operation generating audio frame frequency band frequency domain representation is illustrated by step 501 in figure 6.

In certain embodiments, frequency domain representation is delivered to sound channel analyzer/scrambler 203.

In certain embodiments, scrambler 104 can comprise sound channel analyzer/scrambler 203.Sound channel analyzer/scrambler 203 can be configured to the expression of the sub-band filter receiving multichannel or stereo input.In certain embodiments, sound channel analyzer/scrambler 203 can be configured to analyze frequency-domain audio signals further, and determines and the parameter that each subband is associated relative to stereo or multi-channel audio signal difference.In addition, sound channel analyzer/scrambler can use these parameters, and generation can according to any suitable coding by the monophony of encoding.

In other words, in certain embodiments, parameter is included in the delay estimated between often pair of " delay " subband.In addition, in certain embodiments, follow the discovery of delay, two sound channels can be aligned and for the sound channel compute level difference of aiming at.In certain embodiments, from two sound channels of aiming at, monophonic signal can be formed and utilize monokaryon scrambler to be encoded.In addition in certain embodiments, binaural parameters can be encoded and the ears forming codec extend.In certain embodiments, two continuous print windows can be there are in FFT territory, for it for each frame estimates binaural parameters.Only start 7 length of delays in certain embodiments to be encoded, therefore, every frame altogether 14 length of delays will be encoded.

Stereo parameter and monaural coded signal can be passed to quantizer optimizer 205.

Determine described stereo parameter and generate monophony and the operation that this monophony is encoded is illustrated by step 503 in figure 6.

Relative to Fig. 4, describe the example sound channel analyzer/scrambler 203 according to some embodiments in further detail.In addition relative to Fig. 7, according to the operation of the sound channel analyzer/scrambler 203 that some embodiments show as shown in Figure 4.

In certain embodiments, sound channel analyzer 203 comprises relevant/offset determiner 301.Relevant/offset determiner 301 is configured to skew or the correlativity of the every subband determined between two sound channels (or part of multi-channel audio signal).This skew (or best relative index COR_IND [j]) such as can use code below to determine.

Wherein, value MAXSHIFT is maximum permission skew (this value can based on the pattern of supported microphone arrangement or more simply based on the distance between microphone), PI is π, COR_INIT is that initial correlation or large negative value are used for initialization correlation computations, and COR_BAND_START [] defines the starting point of subband.Vector svec_re [] and svec_im [], for real part and the imaginary values of vector, to be used hereinly defined as follows:

Determine to be correlated with/operation of off-set value illustrates by step 551 in the figure 7.

In certain embodiments, relevant/off-set value can be delivered to monophony maker/scrambler and as stereo channels Parameter transfer to quantizer optimizer.

In addition, in certain embodiments, relevant/off-set value is applied to one in audio track, to provide the time alignment between sound channel.These channel audio signal of aiming at can be delivered to relative energy signal level determiner 301 in certain embodiments.

Relevant/off-set value is used to aim at the operation of sound channel in the figure 7 by step 552 illustrate.

In certain embodiments, sound channel analyzer/scrambler 203 comprises relative energy signal level determiner 301.Relative energy signal level determiner 301 be configured to receive export aim at frequency domain representation, and determine for each subband sound channel between relative signal level.Should be appreciated that, in the following example, single sound channel is to analyzed and process, but this can be extended any amount of sound channel by the multi-channel system pairing be applicable to.

In certain embodiments, the relative level for each frequency band can use following code to calculate.

Wherein, L_FFT is the length of FFT, EPSILON be greater than zero a fractional value to prevent the problem removed by zero.In such embodiments, relative energy signal level determiner effectively generates amplitude for each sound channel (L and R) and determines, then divided by another channel value, to produce relative value on each subband.In certain embodiments, relative energy signal level determiner 301 is configured to export relative energy signal level to coding mode determiner 205.

Determine that the operation of relative energy signal level is in the figure 7 by step 551 illustrate.

Relative energy signal level value can be delivered to monophony maker/scrambler and be delivered to quantizer optimizer as stereo channels parameter in certain embodiments.

In certain embodiments, the difference estimation of (relevant or delay) between (energy) and time between any suitable level can be performed.Such as, two windows can be there are for each frame, postpone and level for these two window estimation.In addition, in certain embodiments, the delay for each window can postpone relevant subbands for each and be estimated.

In certain embodiments, scrambler 104 comprises monophony maker/scrambler 305.Monophony maker is configured to the value receiving sound channel analyzer, such as, from the relative energy signal level of relative energy signal level determiner 301, and carrys out/displacement the level of being correlated with of auto-correlation/offset determiner 303.In addition, in certain embodiments, monophony maker/scrambler 305 can be configured to receive input multi-channel audio signal further.Monophony maker/scrambler 305 can be configured to the difference of delay and level to be applied to multi-channel audio signal, to generate " aligning " sound channel representing this sound signal in certain embodiments.In other words, monophony maker/scrambler 305 can generate the monophonic signal representing the multi-channel audio signal aimed at.Such as, determining to exist in some embodiments of left channel audio signal and right channel audio signal, one in left or right channel audio signal is delayed by relative to another according to determined delay variance, the sound channel then postponed and another channel audio signal by average to generate monophonic signal.But should be appreciated that, in certain embodiments, any suitable monophony generation method can be implemented.

The operation of monophonic signal is generated in the figure 7 by step 555 illustrate from multi-channel signal.

Then monophony maker/scrambler 305 can use any suitable coded format to encode to generated monophonic audio signal in certain embodiments.Such as, in certain embodiments, monophonic audio signal can use enhancing voice service (EVS) monophony coding form to be encoded, and it can comprise adaptive multi-rate-broadband (AMR-WB) codec of bit stream interoperability version.

The operation of encoding mono is in the figure 7 by step 557 illustrate.

Then encoded monophonic signal can be output.In certain embodiments, encoded monophonic signal is output to multiplexer, to carry out merging to form single stream or output with the output of quantizer optimizer 205.In certain embodiments, encoded monophonic signal exports from quantification optimizer 205 dividually.

In certain embodiments, scrambler 104 comprises quantizer optimizer 205.Quantizer optimizer 205 can be configured to receive stereo (difference) parameter determined by sound channel analyzer 203.Then quantizer optimizer 205 can be configured to perform parameter quantize and encode to parameter in certain embodiments, thus they can be output (or will be stored on equipment or pass to another equipment).

The operation of the stereo parameter of quantification and coded quantization is in figure 6 by step 505 illustrate.

Relative to Fig. 5, illustrate in greater detail quantizer optimizer 205.In addition, relative to Fig. 8, the operation of the quantizer optimizer 205 according to some embodiments is shown.

In certain embodiments, quantizer optimizer 205 comprises scalar quantizer 451.Scalar quantizer 451 is configured to receive stereo parameter from sound channel analyzer 203.

The bandwidth (such as 2x12 (WB), 2x (SWB), 2x17 (FB)) of signal will be depended in certain embodiments by the quantity of the level difference of encoding.

Receive the operation of stereo parameter in fig. 8 by step 701 illustrate.

Scalar quantizer can be configured to perform scalar quantization to these values.

Can encode to length of delay with 72 dimension code books in certain embodiments, each has maximum 32 code vectors.It bit rate principle for ears extension can be any value between 0 and 7.0kbps.When the ears that embodiment has 0kbps extend, then the signal of mono version is decoded.In certain embodiments, extend bit rate automatically to be divided with constant ratio (such as 1/3 for delay, and 2/3 for level) between delay and level.

In the following description, describe level coding or quantification, but should be appreciated that in certain embodiments, can extend easily, postpone coding to cover or quantize.

In addition, should be appreciated that, in certain embodiments, ears extend in have two kinds of patterns: True binaural and distance stereo.Far and near stereo mode correspond to a sound channel take as the leading factor and it usually have phonetic material and second sound channel mainly ambient sound time situation.In such circumstances, the frame be in far and near stereo mode has the identical all or nearly all level difference value of mark.

Such as, scalar quantizer 451 can be configured to utilize and be quantized by the quantification partitioned area logarithm value of following array define.

Q＝{-10000.0，-8.0，-5.0，-3.0，-1.0，1.0，3.0，5.0，8.0，100000.0}

Scalar quantizer 451 thus can export and quantize level difference value in zoning and appear at the index value symbol that region is wherein associated.Such as initial quantization index value exports can be as follows:

Index value can be output to frame value analyzer 452 and the device 454 that remaps in certain embodiments.

Quantize with the operation of generating indexes value or symbol shown in Figure 8 by step 703 to difference or stereo parameter or symbol.

In certain embodiments, quantizer optimizer 205 comprises frame value analyzer 452.(in other words frame value analyzer 452 can be configured to the output of reception scalar quantizer 451 in certain embodiments, with find the index value that is associated of quantification partitioned area that is stereo or difference parameter within it), and determine whether that the known mode of only symbol or subset are in this frame.

Such as, as described in this article, when far-near stereophonic signal is encoded (wherein, having main sound channel), frame has all or nearly all level difference with identical mark.

Therefore, in certain embodiments, frame value analyzer 452 can check or analysis frame information, and to determine that this frame whether be all is just all, institute is promising all negative, and nearly all is just, or nearly all be negative.

In certain embodiments, frame value analyzer 452 can determine nearly all interpretation of result, and the value wherein in frame is significantly biased to the mark of plus or minus.Such as, by the occasion of and the appearance of negative value between difference score, and the significantly large range value of record.

In certain embodiments, frame value analyzer 452 can be configured to export to mapping initializer 453 result analyzed.In addition, in certain embodiments, frame value analyzer 452 can be configured to export identical result to frame value/initial mapping indicator 456.

Such as, in certain embodiments, whether frame value analyzer can transmit all about all frames to mapping initializer 453 and frame value/initial mapping indicator 456 is just all, and great majority are just, great majority are negative or all is all negative instruction.

Although analyzing in example is subsequently determine for the one " mark " of initial frame, should be appreciated that, in certain embodiments, the trend of other type can be determined from analyze, the such as trend of low amplitude difference or high-amplitude difference.

In other words, frame value analyzer 452 can be configured to determine whether frame symbol is (or obedience) a kind of trend.This trend can be inferred scheduled or in certain embodiments from data.

Analyze symbol/parameter with the operation of deterministic trend in fig. 8 by step 705 illustrate.

In certain embodiments, quantizer optimizer 205 comprises mapping initializer 453.Map initializer 453 be configured in certain embodiments from frame value analyzer 452 receive the trend followed about frame value instruction (such as all just be all, and nearly all is just, nearly all is negative, or all be all bear).In such embodiments, the initial mapping that initializer 453 can export the mapping of the value of symbol for scalar quantization is mapped.

Such as, map wherein in some embodiments that initializer 453 receives about frame to be all be all positive instruction, initial mapping can be:

Index inputs	0	1	2	3	4	5	6	7	8
										Map and export	(8)	(7)	(6)	(5)	0	1	2	3	4

Map wherein in some embodiments that initializer 453 receives about the frame instruction that to be all be all bears, initial mapping can be:

Index inputs	0	1	2	3	4	5	6	7	8
										Map and export	4	3	2	1	0	(5)	(6)	(7)	(8)

In certain embodiments, the symbol between bracket need not be taken into account, because they do not occur, so only there are 5 different values of symbol to be encoded.These embodiments can depend on how map analysis device performs and to be implemented.Such as, in some cases, except few (not necessarily closest to initial point), all values is all negative/positive.So in this case, the value in bracket can be used, and the long code length by them is punished by this fact that they seldom occur, and can not affect other symbolic coding.Can affirm that all symbols are all that in negative/positive embodiment, the value then in bracket should not be used, because unnecessarily can increase complicacy and the storer of process at some.

Wherein, receive and have instruction for positive nearly all quantization level (level of all quantifications is more than or equal to-1) if map initializer 453 about frame, so initial mapping can be:

Index inputs	0	1	2	3	4	5	6	7	8
										Map and export	(8)	(7)	(6)	2	0	1	3	4	5

Similarly, receive and have instruction for negative nearly all quantization level (level of all quantifications is more than or equal to-1) if map initializer 453 about frame, so initial mapping can be:

Index inputs	0	1	2	3	4	5	6	7	8
										Map and export	5	4	3	1	0	2	(6)	(7)	(8)

In both cases, 6 different values of symbol are only had to be encoded.

Map initializer 453 and initial mapping can be passed to the device 454 that remaps for further adaptation.

Based on analyzing the operation of generation initial mapping in fig. 8 by step 707 illustrate.

In certain embodiments, the optimizer 205 of quantification comprises frame value/initial mapping indicator 456.In certain embodiments, frame value/initial mapping indicator 456 can be configured to receive from frame value analyzer 452 instruction exporting and analyze, and this output is analyzed and can mapped initializer 453 be made for determining initial mapping.Then frame value/initial mapping indicator 456 can generate the signal map for this frame to be delivered to demoder.

Such as, (all is just all to use above-mentioned four kinds of trend at some for far and near pattern, nearly all is just, nearly all is negative, all is all negative) embodiment in, frame value/initial mapping indicator 456 can be configured to generate the pattern position and two signal bits (" an owning " position and " mark " position) that the pattern that used for initial mapping defines.

The setting example of signaling bit is illustrated as can be exemplarily made a summary.

If 1 far and near pattern

1.1., pattern position is set

1.2. check whether that all is just all

1.2.1. all positive initial mapping are used

1.2.2. " owning " position is set to 1

1.2.3. zone bit is set to 0

1.2.4. return

1.3. check whether that all is all negative

1.3.1. all negative initial mapping are used

1.3.2. " owning " position is set to 1

1.3.3. zone bit is set to 1

1.4. return

If 1.5. nearly all is just

1.5.1. loosen nearly all is used to be positive initial mapping

1.5.2. " owning " position is set to 0

1.5.3. zone bit is set to 0

1.5.4. return

1.6. other

1.6.1. by the nearly all initial mapping for bearing loosened

1.6.2. " owning " position is set to 0

1.6.3. arranging zone bit is 1

1.7. return

2. other

2.1., pattern position is set

2.2. general initial mapping is used

Such as example above, signaling can thus by least one bit and at the most 3 bits realize.

The operation of initial mapping/analyzer-indicator is set in fig. 8 by step 709 illustrate.

Quantizer optimizer 205 comprises the device 454 that remaps in certain embodiments.In certain embodiments, (in other words the device 454 that remaps can be configured to the output of reception scalar quantizer 451, with find the index value that is associated of quantification partitioned area that is stereo or difference parameter within it), then according to the frequency of occurrences of this index value, but using the initial mapping from mapping initializer 453, mapping the index value for each frame.

In certain embodiments, the device 454 that remaps can perform frame value analyzer 452 and map the role of initializer 453, to generate initial mapping.In the examples below, before the adapt_GR function shown in entering hereafter, applying initial mapping, wherein, changing further by resetting based on count value.In certain embodiments, adapt_GR function can apply initial mapping to replace the inappreciable initial 1:1 mapping shown in function herein.

The device 454 that remaps such as can analyze each quantized subband difference value for every frame and the rearrangement of execution index value after each analysis.

Such as, the device 454 that remaps can be represented by following C code.

The part indicating * init map* (or initial mapping (initial mapping)) that followed by variable-definition part generates initial mapping, wherein, (in other words symbol or quantizer index export i=0 to i=no_symb-1, the quantity of different quantizer index value, it is 9{0 for the example illustrated above, 1 ..7,8}).

Followed by initial mapping, the part that remaps illustrates: index value or symbol are read into lower frequency sub-bands from higher frequency subbands, and be remapped according to the count value of the symbol in this frame.In example shown here, determine count value by the operation counting of hold mark or index value, wherein, the impact of the symbol in " past " is by the recurrence factor of downward weighting one 0.9.

The recurrence factor, the count increments factor and remap or reset and can change to some extent according to some embodiments.Such as, recurring the factor in certain embodiments can be value lower than 0.9, to give index in the past or the less weighting of value of symbol.Such as, in other embodiments, the recurrence factor can have different values for the coded identification in different past, is namely 0.9 and be 0.8 etc. for the second prior coded symbol for the symbol of previous coding.Such as, in certain embodiments, rearrangement can be carried out like this, and the symbol wherein with same count value is presented.In addition, in certain embodiments, under the situation or situation of equal count value, lower value symbol is sorted or maps to obtain the position with less code length, or vice versa, wherein known from context, and the probability of high level symbol is higher.

Being output in of device 454 of remapping is output to scrambler, wherein this output according to index value or symbol through the appearance in frame of window or subband ranking index value or symbol.

In example described herein, scrambler performs when encoding and occurring and remaps.In certain embodiments, each frame is analyzed, and once whole frame is analyzed, the distribution of then symbol or frequency are used to determine remapping of symbol.

Remap the operation of index value or symbol in fig. 8 by step 711 illustrate according to frequency.

Quantizer optimizer 205 can comprise Golomb-Rice scrambler 455 in certain embodiments.Golomb-Rice scrambler (GR scrambler) 455 is configured to receive by the index value remapped of device generation of remapping or symbol and encodes to index value according to described Golomb-Rice coding method.Therefore Golomb-Rice scrambler 455 exports the code word of the index value representing current and previous in such embodiments.

An example of Golomb-Rice integer code (GR parameter equals 0) is one, wherein exports as follows.

Input	0	1	2	3	4	5	6	7	8
										Export	0	10	110	1110	11110	111110	1111110	11111110	111111110

Should be appreciated that there is the Golomb-Rice integer code of non-zero parameter in certain embodiments, or multiple parameter can be used for encoding to index value.In addition, should be appreciated that, any suitable entropy or integer coding can replace the GR integer code that has such as been described here and be used.

According to the operation of Golomb-Rice coded system generated codeword in fig. 8 by step 713 illustrate.

Then GR scrambler 455 can export stereo code word.In certain embodiments, code word is passed to multiplexer to mix with encoded monophonic audio signal.But in certain embodiments, stereo code word can be passed to be stored or to be passed to miscellaneous equipment as independent stream in certain embodiments.

Export the operation of stereo code word and initial mapping designator in fig. 8 by step 715 illustrate.

In certain embodiments, scrambler comprises signal output 207.Signal as shown in Figure 3 exports and represents such output: it is configured to transmit the encoded stereo parameter that will be stored or will be sent to another equipment.

The output of encoded stereo parameter is in figure 6 by step 507 illustrate.

Therefore, generally, the embodiment about the description of quantizer optimizer is as follows:

-receive difference

-quantize difference with generate represents quantize mapping area symbol (in other words, generate symbol array with encode, x, x [i] in [0, N-1], i=1:M)

-analyze difference/symbol, to determine the trend/defined subgroup of their whether is-symbol sums

-based on analysis, such as determine that symbol is all and is just all and therefore generates the first mapping, generate initial mapping from symbol (index value), thus make the difference being equal to or greater than zero be given less GR code

-generate initial count Count [j]=1, j=0:N-1 (the initial count array for each symbol)

-for each symbol (for i=0:length (x)-1)

-coding x [i]

-more New count:

I.Count [j]=0.9*Count [j], j=0:N-1 (weighting in past)

ii.Count[x[i]]＝Count[x[i]]+1；

-symbol is reset, to make to be primary importance (encoding with the GR code for 0) the most frequently based on the frequency occurred

Terminate

In order to fully illustrate the operation of codec, Fig. 9 and Figure 10 shows the operation of demoder according to some embodiments and demoder.

In certain embodiments, demoder 108 comprises mono decoder 801.Mono decoder 801 is configured to receive encoded monophonic signal in certain embodiments.

Receive the operation of encoded monophonic audio signal in Fig. 10 by step 901 illustrate.

In addition, mono decoder 801 can be configured to use decoding to encoded monophonic audio signal to the inverse process of monophony scrambler shown in scrambler.

The operation of decoding to monophony is in Fig. 10 by step 903 illustrate.

Mono decoder 801 can be configured to export monophonic audio signal to stereo channels maker 809 in certain embodiments.

In certain embodiments, demoder 108 can comprise stereo channels demoder 803.Stereo channels demoder 803 is configured to receive encoded stereo parameter and initial mapping designator.These can be passed to symbol initial order determiner 806.

Receive the operation of encoded stereo parameter and initial mapping designator in Fig. 10 by step 902 illustrate.

In addition, stereo channels demoder 803 can be configured to the stereo channel signals of decoding from entropy code.Such as can use the reverse of code sample as shown here, thus make

Export	0	1	2	3	4	5	6	7	8
										Input	0	10	110	1110	11110	111110	1111110	11111110	111111110

The operation of decoding to stereo parameter is in Fig. 10 by step 904 illustrate.

In certain embodiments, demoder 108 can comprise symbol initial order determiner 806.Symbol initial order determiner can be configured to based on initial mapping designator, production initial mapping, and according to initial mapping, value of symbol is for conversion into initial solution mapping symbols.

Therefore, such as, when initial mapping indicators determines that this frame be all is all positive, initial solution maps and can be:

To remap output	0	1	2	3	4	5	6	7	8
										Input	(8)	(7)	(6)	(5)	0	1	2	3	4

Produce the operation of initial solution mapping in Fig. 10 by step 905 illustrate.

In certain embodiments, symbol initial order determiner 806 is further configured the index value exporting decoding to symbol rearrangement device 807.

In certain embodiments, demoder comprises symbol count renovator 805.Symbol count renovator 805 can be configured to receive present frame stereo channels index value (having decoded and the symbol reset) and use with in demoder use identical counting process to keep the counting of the value of resetting (remapping).In other words, symbol count renovator 805 is configured to carry out refresh counter based on the symbol of decoding current in frame.Symbol count renovator 805 is configured to count for each count resets, thus makes to carry out resetting/remapping for each frame.

(symbol) index count or frequency order can be output to symbol rearrangement device 807.

In certain embodiments, demoder 108 comprises symbol rearrangement device 807.In certain embodiments, symbol or index rearrangement device (de-mapping device) are configured to receiving symbol count update device and export (in other words, index/symbol count frequency), and the decoding symbols received from stereo channels demoder 803 is reset according to symbol frequency.In other words, symbol rearrangement device 807 is configured to original order index value being rearranged to scalar quantizer output.In addition, in certain embodiments, symbol rearrangement device 807 is configured to use the inverse process defined in the quantizer part for the quantizer optimizer in scrambler, is parameter (such as interaural difference/correlation by the index value de-quantization remapped or reset; And level difference/energy differences between ear).

Decoding symbols is reset and de-quantization to quantize the operation of (regeneration) stereo parameter in Fig. 10 by step 906 illustrate for each frame generating solution.

Symbol count renovator 805 can receive the symbol of rearrangement, and more New count.The symbol count data of resetting for next symbol can be output to symbol rearrangement device 807.

The renewal that symbol (index) in frame counts is in Fig. 10 by step 907 illustrate.

Symbol rearrangement device 807 can export to stereo channels maker the index value reset in addition.

Stereo parameter to the output of stereo channels maker in Fig. 10 by step 908 illustrate.

In certain embodiments, demoder comprises stereo channels maker 809, and its configuration receives decoding symbols (stereo parameter) and the decoding mono of rearrangement, and regenerates stereo channels, in other words, level difference is applied to monophony to generate second sound channel.

The operation of stereo channels is generated in Fig. 10 by step 909 illustrate from monophony stereo parameter.

About Figure 11, Figure 12 and Figure 13, in raw format, traditional coding form and the example of binaural audio signal is shown by the form of encoding according to embodiment.

Figure 11 such as shows: the Part II of audio track illustrates the far and near stereo candidate of example, and its middle and upper part sound channel 1001 obviously accounts for dominate and exceedes bottom sound channel 1003.

Figure 12 shows and uses 32kbps core and the extension of 4.5kps ears carry out encoding and use traditional ears coded system to carry out the sound signal from Figure 11 of decoding, and the mistake wherein in coding/decoding process produces listened to bottom sound channel 1103 burr 1105 because coding tracking mistake causes.

Figure 13 shows and uses 32kbps core and the extension of 4.5kps ears to carry out encoding and use embodiments more as above to carry out the sound signal from Figure 11 of decoding.Figure 13 shows bottom sound channel 1203, and it is closer to the bottom sound channel 1003 of Figure 11.

Although above embodiment described the embodiment of the application operated in the codec in equipment 10, but be to be understood that, as described below, the present invention may be implemented as the part of any audio frequency (or voice) codec, comprises any variable bit rate/adaptation rate audio frequency (or voice) codec.Therefore, such as, the embodiment of the application be may be implemented within and can be realized in the audio codec of audio coding by fixing or wired communication path.

Therefore subscriber equipment can comprise such as described in superincumbent the embodiment of the present application those and so on audio codec.

Should be understood that, term " subscriber equipment " is intended to the wireless user equipment covering any suitable type, such as mobile phone, Portable data processing equipment or portable web browser.

In addition, as mentioned above, the element of Public Land Mobile Nerwork (PLMN) also can comprise audio codec.

In general, the various embodiments of the application can be implemented with hardware or special circuit, software, its any combination of logical OR.Such as, some aspects can with hardware implementing, and other side can realize with firmware or the software that can be performed by controller, microprocessor or other computing equipment, but the present invention is not limited thereto.And the various aspects of application can be shown and described as block diagram, process flow diagram or use some other figures to represent, but be well understood that, as nonrestrictive example, these blocks described herein, equipment, system, technology or method can be implemented in hardware, software, firmware, special circuit or logic, common hardware or controller or other computing equipment or its some combination.

The embodiment of the application can realize by the data processor of mobile device (such as in processor entity) executable computer software or by hardware or by the combination of software and hardware.In addition, thus, it should be noted, as any piece of logic flow in the drawings can the logical circuit of representation program step or interconnection, block and function or program step and logical circuit, block and function combination.

Storer can be any type being suitable for local technical environment, and any suitable data storage technology can be used to realize, the memory devices of such as based semiconductor, magnetic storage device and system, optical memory devices and system, read-only storage and removable memory.Data processor can be any type being suitable for local technical environment, and as nonrestrictive example, multi-purpose computer, special purpose computer, microprocessor, digital signal processor (DSP), special IC (ASIC), gate level circuit and one or more based in the processor of polycaryon processor framework can be comprised.

The embodiment of the application can be implemented in various assembly (such as integrated circuit modules).The design of integrated circuit is supermatic process substantially.Complicated and powerful Software tool can be used for logic level design to convert to and is ready to be etched and to be formed semiconductor circuit design on a semiconductor substrate.

Such as design by the Synopsys company in Mountain View city and San Francisco city Cadence the program provided, such program uses the design rule established and the design module storehouse prestored automatically connect up to conductor on a semiconductor die and position parts.Once complete the design for semiconductor circuit, the design of the gained of standardized electronic format (such as Opus, GSDII etc.) can be sent to semiconductor manufacturing facility for manufacture.

As used herein, term " circuit " refers to following all:

A () only has the circuit realiration (realization such as in only mimic channel and/or digital circuit) of hardware;

The combination of (b) circuit and software (and/or firmware), such as: the combination of (i) processor or the part (comprising digital signal processor) of (ii) processor/software, software and storer, work to make equipment such as mobile phone or server perform various function together; And

(c) circuit, a part for such as microprocessor or microprocessor, even if it needs for the software that operates or firmware---this software or firmware also non-physical exist also like this.

This definition of " circuit " is applicable to whole purposes of this term in the application, is included in the purposes in any claim.As another example, as used herein, term " circuit " also covers such realization, and it comprises software and/or firmware that an only processor and/or its part and its (they) enclose.Such as, and if may be used on specific rights to require element, term " circuit " also will cover based band integrated circuit or the application processor integrated circuit of mobile phone or the similar integrated circuit in server, cellular network apparatus or other network equipment.

More than describe by exemplary and nonrestrictive example provide to exemplary embodiment of the present invention not only completely but also the suggestive description of tool.But in view of above description when reading with claims by reference to the accompanying drawings, various amendment and adaptation can become clear to those skilled in the art.But, will fall in the scope of the present invention defined by claims all this type of and the similar amendments of instruction of the present invention.

Claims

1. a method, comprising:

Determine at least one parameter sets defining the difference between at least two audio signal channels;

Analyze at least one parameter sets described to determine initial trend;

Based on described initial trend, map according to first the example mapping at least one parameter sets described, with generate have shut sequence examples of locations through map example; And

Based on the described ordinal position through map example, encode described through map example.

2. the method for claim 1, comprises further:

Determine at least one subsequent parameter;

Depend on through map example frequency distribution and described first map, map subsequent instance with generate have shut sequence position through the example that remaps; And

Based on the described ordinal position through the example that remaps, encode described through the example that remaps.

3. the method as described in claim 1 and 2, wherein said parameter comprise following at least one:

Mistiming between ears; With

Level difference between ears.

4. the method as described in claims 1 to 3, comprises further: the example of parameter described in scalar quantization.

5. the method as described in Claims 1-4, wherein, analyze at least one parameter sets described with determine initial trend comprise determine following at least one:

The entirety of at least one parameter sets described all have on the occasion of;

The entirety of at least one parameter sets described has negative value;

The great majority of at least one parameter sets described have on the occasion of;

The great majority of at least one parameter sets described have negative value;

The entirety of at least one parameter sets described has lower-magnitude value;

The entirety of at least one parameter sets described has higher range value; With

The entirety of at least one parameter sets described has the range value of scope restriction.

6. the method as described in claim 1 to 5, wherein, based on described initial trend, map according to first the example mapping at least one parameter sets described, to generate, there is comprising through map example of shut sequence examples of locations: generate initial mapping, wherein said initial Trend value is assigned lower or comparatively early order.

7. the method as described in claim 1 to 6, comprises further: determine that first through the frequency distribution of map example group.

8. method as claimed in claim 7, wherein, determine that first comprises through the frequency distribution of map example group:

For the described first each in map example group, receive described first through map example value;

Increase progressively and the described first count value be associated through map example value;

To successively decrease the count value be associated with except the described first example value except map example value.

9. the method as described in claim 1 to 8, wherein, depends on the described ordinal position through map example, encodes describedly to comprise through map example: depend on the described ordinal position through map example, is applied to described through map example by Golomb-Rice coding.

10. the method as described in claim 1 to 9, comprises further:

Generate and represent the described first designator mapped; With

Encoded monophony is represented, encoded map example and represent first map designator carry out multiplexing, to generate encoded multi-channel audio signal; With

Export described encoded multi-channel audio signal.

11. 1 kinds of methods, comprising:

From the Part I decoding parametric example of signal and from Part II decoding parametric trend designator; With

Depend on described parameter trend designator, map described examples of parameters with generating solution mapping parameters example, described parameter trend designator is depended in wherein said mapping.

12. methods as claimed in claim 11, comprise further:

To decode another instance parameter from the described Part I of signal; With

Depend on the frequency distribution of described demapping examples of parameters, map another examples of parameters described.

13. methods as described in claim 11 and 12, wherein, comprise from the Part I decoding parametric example of signal: use Golomb-Rice decoding to decode to the Part I of signal.

14. methods as described in claim 11 to 13, comprise: the frequency distribution determining described examples of parameters further.

15. methods as claimed in claim 14, wherein, determine that the frequency distribution of described examples of parameters comprises: for the examples of parameters group of described demapping, keep the counting of described demapping examples of parameters.

16. methods as described in claim 11 to 15, wherein map described examples of parameters and comprise:

Depend on that the order of occurrence that successively decreases for the frequency distribution through the examples of parameters that remaps maps, determine inverse mapping; With

Apply described inverse mapping.

17. 1 kinds of equipment comprising at least one processor and at least one storer, described storer comprises the computer code for one or more program, and at least one storer described and described computer code are configured to together with at least one processor described, described equipment at least be performed:

Analyze at least one parameter sets described to determine initial trend;

Based on described initial trend, map according to described first and map the example of at least one parameter sets, with generate have shut sequence examples of locations through map example; And

18. equipment as claimed in claim 17, make to perform further:

Determine at least one subsequent parameter;

Depend on through map example frequency distribution and described first map, map described subsequent instance with generate have shut sequence position through the example that remaps; And

19. equipment as described in claim 17 and 18, make to perform further:

Generate and represent the described first designator mapped; With

Export described encoded multi-channel audio signal.

20. 1 kinds of equipment comprising at least one processor and at least one storer, described storer comprises the computer code for one or more program, and at least one storer described and described computer code are configured to together with at least one processor described, described equipment at least be performed:

21. equipment as claimed in claim 20, make to perform further:

To decode another instance parameter from the described Part I of signal; With

22. equipment as described in claim 20 and 21, wherein, comprise from the Part I decoding parametric example of signal: use Golomb-Rice decoding to decode to the Part I of signal.

23. 1 kinds of equipment, comprising:

For determining the device of at least one parameter sets of the difference defined between at least two audio signal channels;

For analyzing at least one parameter sets described to determine the device of initial trend;

For based on described initial trend, map the example mapping at least one parameter sets, to generate the device through map example with shut sequence examples of locations according to described first; And

For based on the described ordinal position through map example, the described device through map example of encoding.

24. equipment as claimed in claim 23, comprise further:

For determining the device of at least one subsequent parameter;

For depending on that the frequency distribution and described first through map example maps, map described subsequent instance to generate the device through the example that remaps with shut sequence position; And

For based on the described ordinal position through the example that remaps, the described device through the example that remaps of encoding.

25. equipment as described in claim 23 and 24, comprise further:

For generating the device representing the described first designator mapped; With

For representing encoded monophony, encoded map example and represent first map designator carry out multiplexing, to generate the device of encoded multi-channel audio signal; With

For exporting the device of described encoded multi-channel audio signal.

26. 1 kinds of equipment, comprising:

For from the Part I decoding parametric example of signal and from the device of Part II decoding parametric trend designator; With

For depending on described parameter trend designator, map described examples of parameters with the device of generating solution mapping parameters example, described parameter trend designator is depended in wherein said mapping.

27. equipment as claimed in claim 26, comprise further:

For the device of another instance parameter of decoding from the described Part I of signal; With

For depending on the frequency distribution of demapping examples of parameters, map the device of another examples of parameters described.

28. equipment as described in claim 26 and 27, wherein, the device for the Part I decoding parametric example from signal comprises: to decode the device of decoding to the Part I of signal for using Golomb-Rice.

29. 1 kinds of equipment, comprising:

Sound channel analyzer, is configured at least one parameter sets determining to define the difference between at least two audio signal channels;

Digital analyzer, is configured to analyze at least one parameter sets described to determine initial trend;

Mapper, is configured to based on described initial trend, maps map the example of at least one parameter sets according to first, with generate have shut sequence examples of locations through map example; And

Scrambler, is configured to, based on the described ordinal position through map example, encode described through map example.

30. equipment as claimed in claim 29, wherein:

Described sound channel analyzer is configured to determine at least one subsequent parameter further;

Described mapper is configured to depend on that the frequency distribution and described first through map example maps further, map described subsequent instance with generate have shut sequence position through the example that remaps; And

Described scrambler is configured to, based on the described ordinal position through the example that remaps, encode described through the example that remaps further.

31. equipment as described in claim 29 and 30, comprise further:

Initial mapping indicator, is configured to generate the designator representing described first mapping; With

Multiplexer, is configured to represent encoded monophony, encoded map example and represent that the first designator mapped carries out multiplexing, to generate encoded multi-channel audio signal; With

Export, be configured to export described encoded multi-channel audio signal.

32. 1 kinds of equipment, comprising:

Demoder, is configured to Part I decoding parametric example from signal and from Part II decoding parametric trend designator; With

Mapper, is configured to depend on parameter trend designator, and map described examples of parameters with generating solution mapping parameters example, parameter trend designator is depended in wherein said mapping.

33. equipment as claimed in claim 32, wherein, described demoder is configured to decode another instance parameter from the Part I of signal further; Be configured to described mapper the frequency distribution depending on demapping examples of parameters further, map another examples of parameters described.

34. equipment as described in claim 32 and 33, wherein, described demoder comprises Golomb-Rice demoder.

35. equipment as described in claim 17 to 34, wherein, described parameter comprise following at least one:

Mistiming between ears; With

Level difference between ears.

36. 1 kinds of electronic installations comprising the equipment as described in claim 17 to 35.

37. 1 kinds of chipsets comprising the equipment as described in claim 17 to 35.